Dr. Andrew Huberman, Ph.D. is a Professor of Neurobiology and Ophthalmology at Stanford University School of Medicine. His lab focuses on neural regeneration, neuroplasticity, and brain states such as stress, focus, fear, and optimal performance.
In this episode of the Huberman Lab podcast, Andrew Huberman takes a deep dive into all things related to alcohol, its consumption, its effects on the brain and body, alcoholism, and much more. He breaks down the physiological effects that drinking alcohol has on the brain and body at different levels of consumption and over time, genetic differences that predispose certain individuals to alcoholism, alcohol metabolism, and so much more in this must-listen episode.
Host: Andrew Huberman (@hubermanlab)
Alcohol is both water and fat-soluble – when you drink alcohol it can pass through all the cells and tissues of your body, including the blood-brain barrier (unlike most drugs & substances which attach to the surface of cells)
Three types of alcohol: (1) isopropyl; (2) methyl; (3) ethyl/ethanol – the only one fit for human consumption (though it’s still toxic)
Alcohol is metabolized in the liver (ethanol to acetyl aldehyde to acetate)
Alcohol is empty calories: the process of breaking down alcohol is energetically costly but it contains no nutritive value
Being drunk is a poison-induced disruption in neural circuitry caused by acetyl aldehyde as the alcohol is being metabolized
People with problematic drinking or chronic drinking tend to feel very good after drinking – occasional drinkers will have a briefer state of feeling good which quickly fades
Some acetyl aldehyde and acetate make it across the blood-brain barrier
Slight suppression of neurons in the prefrontal cortex, the area responsible for thinking, planning, suppression of impulsive behavior
Alcohol has a very strong effect in suppressing the neural networks of memory formation and storage (that’s why we forget what happened when we drink)
High levels of alcohol consumption (12-24 drinks per week) absolutely cause degeneration of neurons (specifically the neocortex)
Low to moderate consumption (1-2 drinks per day; 7-14 drinks per week) is also linked to thinning of the neocortex
People who regularly drink 1-2 nights per week experience changes in the neural circuitry of the prefrontal cortex even when not drinking: this is because of an increase in the number of synapses in the connection that control habitual behavior and a reduction in synapses that control behavior
Neural circuits can be modified back to their original state with 2-6 months of abstinence in most casual/social drinkers; those with chronic substance abuse may have long-lasting effects
There is no evidence that 1-2 drinks a month or every few months (or longer) has an effect on neural circuitry
Serotonin is involved in many of the circuits in the brain involved in mood, self-image, and how we see ourselves
When alcohol is converted to acetyl aldehyde it disrupts mood circuitry, making them hyperactive (early inhibition release) until it plummets, and energized mood is suppressed losing alertness and arousal
If increasing amounts of alcohol makes you (or someone around you) feel better and better without falling off, that person is a future alcoholic or has a strong predisposition to become one (the threshold is way higher than most people)
“Blackout drunk” – the activity of neurons in the hippocampus are shutoff so you can’t remember anything
Alcohol changes the relationship between the hypothalamus in the pituitary gland and adrenals which maintains balance in what you see as stressful – the level of cortisol is increased substantially in people who regularly drink
The genes modified by chronic drinking fall along pathways related to the control of serotonin receptors, GABA receptors, and hypothalamic-pituitary axis (combined with the environment)
If you get very red when you drink, chances are you have low alcohol dehydrogenase and get a buildup of toxic effects without being able to metabolize
Alcoholism: there isn’t a single gene but if you have one or more relatives who are chronic abusers of alcohol, you are likely predisposed
People who start drinking at a younger age (13-15) are more likely to develop dependence, regardless of history of alcoholism in their family
If you have a genetic predisposition to alcoholism but delay the drinking age to around 21, the likelihood of alcohol use disorder and alcoholism drops
Your gut runs from your throat to the end of your intestine
The gut and brain communicate via nerve cells (specifically Vagus nerve) and chemical signaling
The gut also communicates via chemical signaling to the liver
The liver also communicates to the brain via chemical and nerve signaling
Alcohol induces a disruption in the gut microbiome by indiscriminately killing bacteria and healthy gut microbiota, which may ultimately cause leaky gut
The metabolism of alcohol in the liver is pro-inflammatory (releasing inflammatory cytokines)
The disruption to major neural circuits causes inflammation of the brain and body and actually leads to the desire to drink more
Replenishing gut microbiota is promising to reduce inflammatory cytokines – 2-4 servings of low sugar fermented foods (kimchi, kefir, etc.)
Sleep after even one drink is not the same quality as without alcohol– when alcohol is present in the bloodstream, the architecture of sleep is disrupted
Disrupted gut-microbiome
Headaches caused by vasoconstriction (alcohol induces vasodilation; when it wears off, it induces vasoconstriction)
  • Be careful taking NSAIDs after drinking – your liver is already taking a beating from the alcohol
Ingesting more alcohol will alleviate a hangover, but an even worse hangover will ensue – bad idea!
Deliberate cold exposure will increase epinephrine and may help with alcohol clearance in the brain and bloodstream
  • Important note: alcohol does lower core body temperature so be careful if you’ve been drinking because temperature regulation is off – don’t cold plunge while drinking
Alcohol is a diuretic so make sure you have plenty of electrolytes, even if you just had 1-2 drinks the night before (the night of drinking, have 1-2 glasses of water for every alcoholic beverage)
Your drink selection matters! And it’s not because of the sugar content, it’s the congeners (nitrates and other ingredients) – beer is least likely to cause a hangover; brandy is at the top of the list
  • Lowest to highest: beer – vodka – gin – white wine – whiskey – rum – red wine – brandy
There’s no magic cure for hangovers!
Tolerance: reduced effects of alcohol with repeated exposure, mainly caused by neurotransmitters in the brain
When people start drinking, there’s an increase in dopamine and serotonin at the beginning of alcohol exposure
With increased tolerance, the negative effects of alcohol and feeling good are longer and more robust – but – there’s also a shrinking of the feel good blip that happens at the beginning
Alcohol moves into the bloodstream within minutes
If you eat something (with carbohydrates, fats, and protein) prior to drinking or while drinking, it will slow the absorption of alcohol into the bloodstream, so you won’t feel as drunk as fast – but this is not true if you eat after drinking
If you’re drunk and eat something, it won’t help blunt what you already drank but will blunt the effects of anything additional you drink after
Don’t drink while pregnant – any amount, no matter what the internet says
Alcohol is a mutagen that has incredible potential to damage developing baby
The early postnatal brain is incredibly plastic
The risk of fetal alcohol syndrome (FAS) is real, and the amount of alcohol needed is unknown – the safest level during pregnancy is zero
Alcohol promotes aromatases of androgens to estrogen
Accelerated or abnormal conversion of testosterone to estrogen can lead to gynecomastia, diminished sex drive, increased fat storage
The truth about resveratrol (in red wine): the amount you’d need for any therapeutic effect is more than anyone should consume
The best amount of alcohol to drink is no alcohol
Alcohol increases cancer risk – taking folate and B12 may slightly help the formation of tumors (but won’t offset)
Alcohol exposure leads to decreases in testosterone over time (despite studies looking at acute exposure and slight increases)
Articles Mentioned
  • Associations between alcohol consumption and gray and white matter volumes in the UK Biobank (Nature Communications)
  • Gut Microbiota at the Intersection of Alcohol, Brain, and the Liver (Journal of Clinical Medicine)
  • Tolerance to alcohol: A critical yet understudied factor in alcohol addiction (Pharmacology Biochemistry and Behavior)
  • Associations Between Drinking and Cortical Thickness in Younger Adult Drinkers: Findings From the Human Connectome Project (Alcoholism: Clinical and Experimental Research)
  • Moderate Alcohol Consumption and the Risk of Breast Cancer (The New England Journal of Medicine)
  • Can alcohol promote the aromatization of androgens to estrogens? A review (Alcohol)
Additional Resources Discussed
  • Examine – Alcohol & Hangover